CN112250858B

CN112250858B - Method for preparing flame-retardant polymer polyol, application and polyurethane foam plastic prepared by using flame-retardant polymer polyol

Info

Publication number: CN112250858B
Application number: CN202010891576.7A
Authority: CN
Inventors: 姜明; 刘洋; 李传亮; 秦承群; 隋美玉; 李付国
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2022-07-12
Anticipated expiration: 2040-08-31
Also published as: CN112250858A

Abstract

The invention relates to a method for preparing flame-retardant polymer polyol by using phosphoramide, which mainly comprises the following steps: a. in the nitrogen atmosphere, phosphoryl dichloride and organic diamine react, then an acid-binding agent is added, and after the reaction is carried out for 2 hours at the temperature of 60 ℃, colorless transparent solution is obtained by filtration. b. Adding a formaldehyde solution into the phosphoramide solution obtained in the step a, and heating for reaction for a period of time; and mixing the obtained solution with polyether polyol, heating for complete reaction, and vacuumizing to remove residual monomers to obtain the flame-retardant polymer polyol, wherein the flame-retardant polymer polyol contains 6-9% of nitrogen and 3-5% of phosphorus by weight of the polymer polyol. The polyurethane foam plastic prepared from the flame-retardant polymer polyol has the advantages of foaming foam oxygen index of about 30%, good flame-retardant property and low smoke amount.

Description

Method for preparing flame-retardant polymer polyol, application and polyurethane foam plastic prepared by using flame-retardant polymer polyol

Technical Field

The invention belongs to the field of polyurethane synthetic materials, and particularly relates to a method for preparing flame-retardant polymer polyol by using phosphoramide.

Background

The polyurethane material has the advantages of excellent chemical corrosion resistance, weather resistance, excellent machining performance and the like, and is widely applied to the fields of clothes, shoes and hats, building outer walls, pipelines, aerospace, furniture, automobiles, medical treatment and the like. However, the common polyurethane material has low oxygen index and is easy to burn, and a large amount of toxic smoke is released during burning, thereby bringing great harm to the life and property safety of people. The polyether polyol is one of the main raw materials of polyurethane, and if the polyether polyol contains a flame-retardant element, the flame-retardant property of the polyurethane material can be effectively improved. At present, the flame-retardant polyether polyol is mainly divided into an additive type and a reactive type, wherein the additive type means that an inorganic or organic flame retardant is directly added into a raw material during polyurethane foaming, the method has the advantages of simple process and low cost, but the method has large flame retardant consumption and poor flame retardant performance, and meanwhile, the flame retardant is uneven in distribution and poor in stability in a polyurethane material and is easy to lose, and the mechanical property of the material is also seriously reduced. The reactive type is that flame-retardant elements are introduced into polymer polyol through chemical reaction, and the flame-retardant elements are uniformly distributed and have good stability, so that the polyurethane material has excellent flame-retardant performance.

The flame retardant elements mainly comprise halogen, nitrogen, phosphorus, boron, silicon and the like, wherein halogen-containing polyether polyol is developed earlier and has already been industrialized, but toxic gas hydrogen halide is released during combustion to cause breathing difficulty of people and even can cause suffocation death of people, so the development direction in the future is to develop halogen-free flame retardant polyether polyol. The phosphorus element can generate a series of phosphorus-containing acid during combustion, carbon-containing organic matters can be dehydrated into carbon, the generated carbon layer is compact and is not easy to combust, and meanwhile, combustible gas can be prevented from entering a combustion phase, so that the combustion is stopped. The nitrogen element can generate non-combustible gas during combustion, on one hand, the temperature of the surface of the material can be reduced by decomposing and absorbing heat, and on the other hand, the non-combustible gas can also dilute oxygen and combustible gas, so that a better flame retardant effect is achieved. The phosphorus and nitrogen synergistic flame-retardant polyether polyol can combine the advantages of the phosphorus and nitrogen synergistic flame-retardant polyether polyol and the flame-retardant polyether polyol, has higher flame-retardant efficiency, and is the main development direction of the flame-retardant polyether polyol.

CN1583829A discloses a method for preparing flame-retardant polyether by using melamine, which comprises the steps of reacting melamine, formaldehyde and alcohol amine together to obtain melamine liquid, mixing the melamine liquid with polyether polyol, and adding isocyanate to obtain the flame-retardant polyether polyol, wherein the flame-retardant polyether polyol only contains nitrogen elements and has poor flame-retardant property. CN102391516A discloses a synthesis of a phosphorus-containing halogen-containing flame-retardant polyester polyol, which is formed by the polycondensation of halogen-containing polyol and phosphorus oxychloride, but the flame-retardant polyester polyol contains halogen and emits a large amount of toxic gas during combustion. CN201510766576.3 discloses a preparation and application of nitrogen-phosphorus structure type flame-retardant polyether polyol, formaldehyde, melamine and phosphite ester are reacted and then added into polyether polyol to obtain the polyether polyol terminated by hydroxymethyl melamine phosphite ester, and due to the limitation of hydroxyl and steric hindrance on polyether, the reaction is not only difficult to carry out, but also the hydroxymethyl melamine phosphite ester capable of reacting with polyether polyol is less, so that the application value is not too large.

Phosphoramide is a typical intumescent flame retardant, can significantly improve the flame retardant property of polyurethane foam, and does not contain halogen, so that no toxic gas is emitted during combustion, thereby attracting wide attention of people. Synthesis of phosphamide flame retardants such as Xinmeihua and application thereof in rigid polyurethane foam [ J ] Polymer Material science and engineering, 2013,32(1),19-24) Synthesis of 3 phosphamide flame retardants from dimethyl phosphite, diethylamine, n-butylamine, and cyclohexylamine, and application thereof in the field of flame retardancy of rigid polyurethane foam. Preparation, characterization and application of two novel polyamide flame retardants of Lixiaoqing [ D ]. Beijing university of physical and chemical industries, 2015.) Lichongqing takes phenyl dichlorophosphate as a raw material, and carries out solution polycondensation reaction with p-phenylenediamine and m-phenylenediamine in N, N-Dimethylformamide (DMF) to obtain two novel phosphoramide flame retardants. CN105683337B discloses a flame retardant with a phosphoramidate structure for polyurethane foam or polyurethane elastomer, which has excellent flame retardant property and other excellent properties. However, such additive flame retardants of the prior art have a common disadvantage: due to poor compatibility of the flame retardant and the base material, the phenomena of precipitation and migration loss of the flame retardant inevitably exist, so that the flame retardance of the material is lost.

Therefore, there is still a need for a method for preparing a flame retardant polymer polyol by using phosphoramide, which comprises polymerizing phosphoramide and formaldehyde in polyether polyol to uniformly disperse the polymer in the polyether polyol, and simultaneously reacting a part of the polymer with the polyether polyol, so that the polymer polyol can be stably stored for a long time without sedimentation.

Disclosure of Invention

The invention aims to solve the technical problems of poor flame retardant property and toxic gas release caused by high temperature halogen containing of the existing flame retardant polymer polyol, and provides a method for preparing the flame retardant polymer polyol by using phosphoramide.

Another object of the present invention is to provide such flame retardant polymer polyols prepared with phosphoramides and their use in polyurethane synthetic materials.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for preparing flame-retardant polymer polyol by using phosphoramide is characterized by comprising the following steps:

1) preparation of phosphoramide: in an inert atmosphere, dissolving phosphoryl dichloride in an organic solvent to obtain a solution A; dissolving organic diamine in an organic solvent, dropwise adding the organic diamine into the solution A, reacting at-30-20 ℃ for 1-6 h, preferably at-5 ℃ for 1-3 h, heating to 30-100 ℃ for reaction for 0.5-6 h, preferably at 40-60 ℃ for 1-3 h; then adding an acid-binding agent, reacting at 30-100 ℃ for 1-6 h, preferably at 40-60 ℃ for 1-3 h, and finally filtering to obtain a colorless and transparent phosphoramide solution;

2) polymerization reaction: adding a formaldehyde solution into the phosphoramide solution obtained in the step 1), heating to 60-80 ℃, and reacting for 0.5-2 h to obtain a solution B; mixing the obtained solution B with polyether polyol, heating to 60-160 ℃, and reacting for 1-6 h, preferably for 1-3 h at 80-100 ℃; and then vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 90-120 ℃ to remove residual monomers to obtain the flame-retardant polymer polyol.

In a preferred embodiment, a reaction promoter is further added to the solution A of the step 1), and the reaction promoter is selected from halogen metal salts; preferably an iodide salt or a bromide salt, more preferably potassium iodide or sodium iodide; the addition amount of the reaction promoter is 0.0001-2%, preferably 0.05-0.2% of the total mass of the phosphamide solution.

In a particular embodiment, the phosphoryl dichloride has the formula:

wherein R is C₁～C₈Alkyl, alkenyl, alkynyl, cycloalkyl or C₆～C₈Any of the phenyl groups of (1), preferably C₁～C₈Alkyl or C₆～C₈A phenyl group of (a).

In a particular embodiment, the organic solvent is selected from aprotic solvents of ethers, amides, halogenated hydrocarbons, saturated alkanes, aromatic hydrocarbons or sulfones; preferably 2-6 carbon-containing ether or cyclic ether, 3-6 carbon-containing amide or alkyl substituted amide, 1-3 carbon-containing saturated chloroalkane, halogenated benzene, 3-13 carbon-containing sulfone; more preferably one or more of tetrahydrofuran, dimethylformamide, dimethylacetamide, dioxane and dichloromethane; further preferably dioxane; the phosphoryl dichloride and the organic diamine are dissolved in different or same organic solvents, the mass ratio of the organic solvent used for dissolving the organic diamine to the organic diamine is 2: 1-6: 1, preferably 2: 1-3: 1, and the mass ratio of the organic solvent to the phosphoryl dichloride in the solution A is 2: 1-6: 1, preferably 2: 1-3: 1.

In a particular embodiment, the organic diamine is selected from one or more of ethylenediamine, 1,2 or 1,3 diaminopropane, 1,4 diaminobutane, 1,6 diaminohexane, p-phenylenediamine; preferably, the molar ratio of the organic diamine to the phosphoryl dichloride is 2: 1-3: 1.

In a specific embodiment, the acid scavenger is selected from one or more of sodium carbonate, triethylamine, pyridine, trimethylamine; preferably, the molar ratio of the acid-binding agent to the phosphoryl dichloride is 2: 1-2.1: 1.

In a specific embodiment, the formaldehyde solution is a 37% aqueous solution, and the molar ratio of formaldehyde to phosphoramide is 1: 1-2: 1, preferably 1.2:1-1.6: 1; the mass ratio of the total amount of the formaldehyde and the phosphoramide to the polyether polyol is 0.1-0.6.

In a particular embodiment, the polyether polyol is one or more of a polyethylene oxide polyol and a polypropylene oxide polyol; preferably, the polyether polyol has a hydroxyl value of 20-60, a functionality of 2-6 and a molecular weight of 2000-8000.

In another aspect of the invention, the flame-retardant polymer polyol prepared by the method has a nitrogen content of 6-9% and a phosphorus content of 3-5% based on the weight of the polymer polyol, and can be used in the field of polyurethane synthetic materials.

In still another aspect of the present invention, a polyurethane foam prepared from the flame retardant polymer polyol is characterized in that the polyurethane foam has a foam oxygen index of about 30%.

Compared with the prior art, the invention has the following advantages:

1) according to the invention, the polymer of phosphoramide and formaldehyde is uniformly dispersed in the polyether polyol, and part of the polymer reacts with the polyether polyol, so that the polymer polyol can be stably stored for a long time without sedimentation, the problem that an additive flame retardant is easy to migrate is solved, and meanwhile, the polymer particles can effectively improve the bearing capacity and resilience of the polyurethane foam plastic.

2) The flame-retardant polymer polyol prepared by the invention contains two flame-retardant elements of phosphorus and nitrogen at the same time, has good synergistic effect, and the oxygen index of the polyurethane foam plastic prepared by the method reaches about 30 percent.

3) The flame-retardant polymer polyol prepared by the invention does not contain halogen, does not release toxic gas during combustion, and has low smoke generation.

4) The organic diamine used for preparing the flame-retardant polymer polyol is saturated primary amine and has a promoting effect on foaming, so that the foaming formula has high latitude and strong applicability, and particularly has a good foaming effect under a high-water and high-TDI system.

Detailed Description

The following examples will further illustrate the method provided by the present invention in order to better understand the technical solution of the present invention, but the present invention is not limited to the listed examples, and should also include any other known modifications within the scope of the claims of the present invention.

A method of making a flame retarded polymer polyol with a phosphoramide, comprising the steps of:

1) preparation of phosphoramide: dissolving phosphorus oxychloride in an organic solvent in an inert atmosphere, dropwise adding organic diamine dissolved in the organic solvent into the solution, reacting at the temperature of-30-20 ℃ for 1-6 h, and then heating to 30-100 ℃ for reacting for 0.5-6 h h; and then adding an acid binding agent, reacting at 30-100 ℃ for 1-6 h, and filtering to obtain a colorless and transparent solution.

2) Polymerization reaction: adding a formaldehyde solution into the phosphoramide solution obtained in the step 1), heating to 60-80 ℃, and reacting for 0.5-2 h; mixing the obtained solution with polyether polyol, heating to 80-100 ℃, and reacting for 1-3 h; and (3) vacuumizing to remove residual monomers under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 90-120 ℃ to obtain the flame-retardant polymer polyol.

In another embodiment of the present invention, a method for preparing a flame retarded polymer polyol using a phosphoramide comprises the steps of:

1) preparation of phosphoramide: in the nitrogen atmosphere, phosphoryl dichloride is dissolved in an organic solvent, and a reaction promoter is added to obtain a solution A; dissolving organic diamine in an organic solvent, dropwise adding the organic diamine into the solution A, reacting for 1-3 h at-5 ℃, and then heating to 40-60 ℃ for reacting for 1-3 h; then adding an acid-binding agent, reacting at 40-60 ℃ for 1-3 h, and finally filtering to obtain a colorless and transparent phosphamide solution;

2) polymerization reaction: adding a formaldehyde solution into the phosphoramide solution obtained in the step 1), heating to 60-80 ℃, and reacting for 0.5-2 h to obtain a solution B; mixing the obtained solution B with polyether polyol, and heating to 80-100 ℃ for reaction for 1-3 h; and then vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 90-120 ℃ to remove residual monomers to obtain the flame-retardant polymer polyol.

That is, the reaction of the organic diamine with phosphoryl dichloride in step 1) may be carried out as it is or in the presence of a reaction promoter, which is preferably used. The reaction promoter is selected from halogen metal salts, preferably iodide salts or bromide salts, particularly preferably potassium iodide or sodium iodide. The addition amount of the reaction accelerator is preferably 0.0001-2%, preferably 0.05-0.2% of the total mass of the phosphoramide solution. The total mass of the phosphoramide solution comprises the mass of the phosphoramide obtained by the reaction and the total mass of all the organic solvents; wherein, the quality of the phosphoramide can be obtained by theoretical calculation according to the adding amount of the organic diamine and the phosphoryl dichloride.

In the invention: the phosphoryl dichloride added in the step 1) has a structural formula as follows:

wherein R is C₁～C₈Alkyl, alkenyl, alkynyl, cycloalkyl or C₆-C₈Phenyl of (2), preferably C₁～C₈Alkyl or C₆-C₈Such as R includes, but is not limited to, methyl, ethyl, cyclohexyl, phenyl or benzyl, and the like.

The organic solvent used in step 1) is an aprotic solvent such as ether, amide, halogenated hydrocarbon, saturated alkane, aromatic hydrocarbon, sulfone and the like, preferably ether or cyclic ether containing 2 to 6 carbons, amide or alkyl substituted amide containing 3 to 6 carbons, saturated chloroalkane containing 1 to 3 carbons, halogenated benzene, sulfone containing 3 to 13 carbons, more preferably one or more of tetrahydrofuran, dimethylformamide, dimethylacetamide, dioxane and dichloromethane, and further preferably dioxane. Of these, phosphoryl dichloride and an organic diamine are preferably dissolved in the same organic solvent, but may be dissolved in different organic solvents selected from the above.

The organic diamine added in the step 1) is one or more of ethylenediamine, 1, 2-diaminopropane, 1, 3-diaminopropane, 1, 4-diaminobutane, 1, 6-diaminohexane and p-phenylenediamine, and is preferably ethylenediamine.

The acid-binding agent added in the step 1) is one or more of sodium carbonate, triethylamine, pyridine and trimethylamine, and triethylamine is preferred.

Wherein, the phosphoric acid dichloride and the organic diamine in the step 1) can generate hydrochloric acid, and an acid-binding agent is required to be added to remove the hydrochloric acid so as to avoid adverse effects on the subsequent reaction. It should be noted that, when the acid-binding agent is sodium carbonate, the acid-binding agent sodium carbonate solid can be added after the reaction of the phosphoryl dichloride and the organic diamine, and then the step 1) is: in an inert atmosphere, dissolving phosphoryl dichloride in an organic solvent to obtain a solution A; dissolving organic diamine in an organic solvent, dropwise adding the organic diamine into the solution A, reacting at-30-20 ℃ for 1-6 h, preferably at-5 ℃ for 1-3 h, heating to 30-100 ℃ for reaction for 0.5-6 h, preferably at 40-60 ℃ for 1-3 h; adding an acid-binding agent, reacting at 30-100 ℃ for 1-6 h, preferably at 40-60 ℃ for 1-3 h, and finally filtering to obtain a colorless and transparent phosphamide solution.

When the acid-binding agent is triethylamine, pyridine or trimethylamine, the acid-binding agent is added in advance and participates in the reaction, and the acid-binding agent is removed in vacuum after the reaction is finished, wherein the step 1) comprises the following steps: in an inert atmosphere, dissolving phosphoryl dichloride in an organic solvent, and adding an acid-binding agent to obtain a solution A; dissolving organic diamine in an organic solvent, dropwise adding the organic diamine into the solution A, reacting at-30-20 ℃ for 1-6 h, preferably at-5 ℃ for 1-3 h, heating to 30-100 ℃ for reaction for 0.5-6 h, preferably at 40-60 ℃ for 1-3 h; vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 90-120 ℃ to remove the solvent, dissolving the obtained solid in water, stirring and filtering to obtain a white solid.

Wherein the molar ratio of the organic diamine to the phosphoryl dichloride in the step 1) is 2: 1-3: 1; the mass ratio of the organic solvent used for dissolving the organic diamine to the organic diamine is 2: 1-6: 1, preferably 2: 1-3: 1, and the mass ratio of the organic solvent to the phosphoryl dichloride in the solution A is 2: 1-6: 1, preferably 2: 1-3: 1; the molar ratio of the acid-binding agent to the phosphoryl dichloride is 2: 1-2.1: 1.

In the step 2), the formaldehyde solution is a 37% aqueous solution, and the molar ratio of formaldehyde to phosphoramide is 1: 1-2: 1, preferably 1.2:1-1.6: 1. The mass ratio of the total amount of formaldehyde and phosphoramide to the polyether polyol is 0.1-0.6. Wherein the mass or the mole number of the phosphoramide can be obtained by theoretical calculation according to the adding amount of the organic diamine and the phosphoryl dichloride.

The polyether polyol used in step 2) may be selected from polyether polyols conventional in the art, preferably one or more of polyethylene oxide polyols and polypropylene oxide polyols. Preferably, the polyether polyol used has a hydroxyl value of 20 to 60, a functionality of 2 to 6 and a molecular weight of 2000 to 8000.

The invention will now be further elucidated with reference to the following examples, without being limited thereto.

The polyether polyols used in the examples were as follows:

polyether polyol 1: the propylene oxide/ethylene oxide polyether polyol with the number average molecular weight of 3000 and started by glycerin has a hydroxyl value of 56KOH/g and viscosity of 350-500 mP & s/25 ℃.

Polyether polyol 2: propylene oxide/ethylene oxide polyether polyol with the number average molecular weight of 4800 and initiated by glycerin has the hydroxyl value of 35KOH/g and the viscosity of 500-700 mP & s/25 ℃.

Polyether polyol 3: propylene oxide/ethylene oxide polyether polyol with the number average molecular weight of 3500 and initiated by propylene glycol has a hydroxyl value of 32KOH/g and a viscosity of 400-550 mP s/25 ℃.

Polyether polyol 4: propylene oxide/ethylene oxide polyether polyol having a number average molecular weight of 2500 and initiated with propylene glycol, having a hydroxyl value of 45KOH/g, a viscosity of 350-450 mPs/25 DEG C

Polyether polyol 5: the epoxy propane/ethylene oxide polyether polyol with the number average molecular weight of 6400 and initiated by pentaerythritol has a hydroxyl value of 35KOH/g and viscosity of 850-1000 mP & s/25 ℃.

Polyether polyol 6: the propylene oxide/ethylene oxide polyether polyol with the number average molecular weight of 4500 and initiated by pentaerythritol has a hydroxyl value of 50KOH/g and viscosity of 500-700 mP & s/25 ℃.

Other organic solvents, phosphoryl dichloride, organic diamine, formaldehyde, reaction promoters and the like used in the examples are all commercially available reagents and can be obtained by analytical purification.

The specifications of the reagents used for polyurethane foam synthesis are as follows:

POP 2140: a product sold in the market of Wanhua chemistry, a polyether polyol which takes a copolymer of styrene and acrylonitrile as an organic filler and is called polymer polyol.

F3135 commercial product of Wanhua chemical, propylene oxide/ethylene oxide polyether polyol having a number average molecular weight of 4800 and being initiated with glycerol, a hydroxyl value of 35KOH/g, a viscosity of 500 to 550mP s/25 DEG C

The silicone surfactant, triethylene diamine 33% diethylene glycol solvent catalyst, bis (ditolyl ethyl) ether 70% solution, diethanolamine, TM20, etc. were all commercially available.

The test method is as follows:

oxygen index: the combustion behavior of GB/T2046.2-2009 plastics was determined by the oxygen index method.

Smoke density: GB/T20286-2006 monomer burn test of construction materials or articles.

Wherein, the content of phosphorus and nitrogen in the polymer polyol is obtained by theoretical calculation.

Example 1

(1) In a nitrogen atmosphere, 111g of phenylphosphoryl dichloride is dissolved in 223g of tetrahydrofuran, 0.2g of sodium iodide is added, then 86g of ethylenediamine dissolved in 172g of tetrahydrofuran is added into the solution dropwise, the reaction is carried out for 3h at the temperature of-5 ℃, and then the reaction is carried out for 3h by heating to 50 ℃; then 121g of sodium carbonate solid was added and after 3h of reaction at 50 ℃ filtered a colorless transparent solution was obtained.

(2) Adding 65g of 37% formaldehyde water solution into the phenyl phosphoryl diethylene diamine solution obtained in the step (1), heating to 80 ℃, and reacting for 0.5 h; mixing the obtained solution with 350g of polyether polyol 1, heating to 100 ℃, and reacting for 1 h; and (3) vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 100 ℃ to remove residual monomers to obtain flame-retardant polymer polyol with the viscosity of 3176mP & s/25 ℃ and the solid content of 30%, wherein the phosphorus content of the product is 3.6% and the nitrogen content of the product is 6.4%.

Example 2

(1) Dissolving 80g of methylphosphoryl dichloride in 199g of dioxane in a nitrogen atmosphere, adding 0.36g of sodium iodide, then dropwise adding 101g of propylenediamine dissolved in 252g of dioxane into the solution, reacting at the temperature of 0 ℃ for 2 hours, and then heating to 40 ℃ for reaction for 3 hours; thereafter, 152g of sodium carbonate solid was added and reacted at 40 ℃ for 3 hours and then filtered to obtain a colorless transparent solution.

(2) Adding 66g of 37% formaldehyde aqueous solution into the methylphosphoryl dipropylenediamine solution obtained in the step (1), heating to 60 ℃, and reacting for 2 hours; mixing the obtained solution with 350g of polyether polyol 2, heating to 90 ℃, and reacting for 2 h; and (3) vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 110 ℃ to remove residual monomers to obtain the flame-retardant polymer polyol with the viscosity of 2886mP & s/25 ℃ and the solid content of 30%, wherein the phosphorus content of the product is 4.2% and the nitrogen content is 7.6%.

Example 3

(1) Dissolving 80g of ethyl phosphoryl dichloride in 240g of tetrahydrofuran in a nitrogen atmosphere, adding 0.14g of sodium iodide and 124g of triethylamine, then adding 198g of p-phenylenediamine dissolved in 595g of tetrahydrofuran dropwise into the solution, reacting at the temperature of 5 ℃ for 2h, then heating to 60 ℃ for reacting for 2h, vacuumizing under the pressure of-0.09 MPa and the temperature of 50 ℃ to remove the solvent, dissolving the obtained solid in 600g of water, stirring for 10min, and filtering to obtain a white solid.

(2) Dissolving the obtained ethyl phosphoryl diphenyldiamine solid in the step (1) in 320g of tetrahydrofuran, adding 198g of 37% formaldehyde water solution, heating to 70 ℃, and reacting for 1 h; mixing the obtained solution with 325g of polyether polyol 3, heating to 80 ℃, and reacting for 3 h; and (3) vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 100 ℃ to remove residual monomers to obtain flame-retardant polymer polyol with the viscosity of 3129mP & s/25 ℃ and the solid content of 35%, wherein the phosphorus content of the product is 3.8% and the nitrogen content is 6.8%.

Example 4

(1) 149g of phenylphosphoryl dichloride is dissolved in 893g of dioxane in a nitrogen atmosphere, 0.25g of potassium iodide is added, then 101g of ethylenediamine dissolved in 604g of dioxane is added into the solution dropwise, and the solution reacts for 6 hours at the temperature of minus 30 ℃ and then is heated to 80 ℃ to react for 1 hour; then 162g of sodium carbonate solid was added and after 1h of reaction at 80 ℃ filtered a colorless transparent solution was obtained.

(2) Adding 86g of 37% formaldehyde water solution into the phenyl phosphoryl diethylene diamine solution obtained in the step (1), heating to 60 ℃, and reacting for 2 h; mixing the obtained solution with 300g of polyether polyol 4, heating to 160 ℃, and reacting for 1 h; and (3) vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 110 ℃ to remove residual monomers to obtain the flame-retardant polymer polyol with the viscosity of 4192mP & s/25 ℃ and the solid content of 40%, wherein the phosphorus content of the product is 4.8% and the nitrogen content of the product is 8.6%.

Example 5

(1) Dissolving 122g of cyclohexyl phosphoryl dichloride in 488g of dimethylformamide in a nitrogen atmosphere, adding 0.5g of potassium iodide, then adding 126g of propane diamine dissolved in 505g of dimethylformamide dropwise into the solution, reacting at the temperature of 10 ℃ for 3 hours, and then heating to 30 ℃ for 6 hours; thereafter 129g of sodium carbonate solid were added and after 6h of reaction at 30 ℃ filtered a colorless transparent solution was obtained.

(2) Adding 79g of 37% formaldehyde aqueous solution into the cyclohexyl dipropylene phosphoryl diamine solution obtained in the step (1), heating to 80 ℃, and reacting for 1 h; mixing the obtained solution with 325g of polyether polyol 5, heating to 100 ℃, and reacting for 1.5 h; and (3) vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 120 ℃ to remove residual monomers to obtain flame-retardant polymer polyol with the viscosity of 3415 mPs/25 ℃ and the solid content of 35%, wherein the phosphorus content of the product is 3.8% and the nitrogen content of the product is 6.8%.

Example 6

(1) Under nitrogen atmosphere, 112g of butyl phosphoryl dichloride is dissolved in 247g of dimethylformamide, 129g of triethylamine is added, then 100g of ethylenediamine dissolved in 220g of dimethylformamide is added into the solution dropwise, the reaction is carried out at the temperature of 20 ℃ for 1h, then the temperature is increased to 100 ℃ for 0.5h, the solvent is removed by vacuumizing under the conditions that the pressure is-0.09 MPa and the temperature is 120 ℃, the obtained solid is dissolved in 800g of water, the stirring is carried out for 10min, and the white solid is obtained by filtering.

(2) Dissolving the butyl phosphoryl diethylenediamine solid obtained in the step (1) in 380g of dimethylformamide, adding 62g of 37% formaldehyde aqueous solution, heating to 70 ℃, and reacting for 2 h; mixing the obtained solution with 350g of polyether polyol 6, heating to 90 ℃, and reacting for 3 h; and (3) vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 120 ℃ to remove residual monomers to obtain flame-retardant polymer polyol with the viscosity of 2736mP & s/25 ℃ and the solid content of 30%, wherein the phosphorus content of the product is 4.0% and the nitrogen content is 7.2%.

The raw materials used in the above examples are shown in Table 1

Table 1 table of raw materials used in examples

And (3) testing the stability:

the polymer polyols synthesized in examples 1-6 were not delaminated after standing at 30 ℃ for 6 months, which indicates that the flame retardant polymer polyol prepared by the present invention can be stably stored for a long time without sedimentation, and overcomes the problem of easy migration of additive flame retardants. The reactive system of the invention uniformly disperses the polymer of the reaction of the phosphoramide and the formaldehyde in the polyether polyol, and part of the polymer reacts with the polyether polyol to form a relatively stable structure, so that the reactive system can be stably stored for a long time without sedimentation.

And (3) testing the flame retardant property:

with the polymer polyol of the brand POP2140 produced by Wanhua chemical Co., Ltd as a comparison, the flame retardant polymer polyol products or POP2140 in examples 1 to 6 were prepared into polyurethane foams according to the following formulation, and the flame retardant properties thereof were tested.

The polyurethane foam formula comprises the following components:

f3135: 50 portions of

Examples 1-6 or comparative example POP 2140: 50 portions of

Silicone surfactant: 1.0 part

Triethylene diamine 33% diethylene glycol solvent catalyst: 0.4 portion of

Bis (ditolyl ethyl) ether 70% solution: 0.06 part

Diethanolamine: 1.0 part

Water: 2.8 parts of

TM 20: 36.2 parts of

Polyurethane foam synthesis: selecting a TDI/MDI blend reactivity index; 1.05, mixing at high speed, injecting into a 250 x 150 stainless steel die, foaming at room temperature, curing at 50 +/-5 ℃, demolding, standing at room temperature for 7 days, and testing the physical properties.

The resulting polyurethane foams were tested for flame retardancy, the results of which are shown in Table 2

TABLE 2 flame retardancy test results

	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Comparative example
								Limiting oxygen index (%)	28.1	29.6	29.3	31.5	30.2	29.8	18.2
Smoke density (%)	48.4	48.1	47.8	46.3	47.2	47.5	65

It can be seen that the oxygen index of the foamed polyurethane foam prepared from the flame-retardant polymer polyol prepared by the method of the invention can reach about 30 percent, which is much higher than that of the polyurethane foam prepared from the conventional polymer polyol POP 2140; meanwhile, the smoke density is lower than that of the comparative example, which shows that the polyurethane foam plastic prepared by the flame-retardant polymer polyol is more user-friendly in flame-retardant property.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. It will be appreciated by those skilled in the art that modifications or adaptations to the invention may be made in light of the teachings of the present specification. Such modifications or adaptations are intended to be within the scope of the present invention as defined by the claims.

Claims

1. A method for preparing flame-retardant polymer polyol by using phosphoramide is characterized by comprising the following steps:

1) preparation of phosphoramide: in an inert atmosphere, dissolving phosphoryl dichloride in an organic solvent to obtain a solution A; dissolving organic diamine in an organic solvent, dropwise adding the organic diamine into the solution A, reacting for 1-6 h at-30-20 ℃, and then heating to 30-100 ℃ for reacting for 0.5-6 h; adding an acid-binding agent, reacting at 30-100 ℃ for 1-6 h, and finally filtering to obtain a colorless and transparent phosphoramide solution;

2) polymerization reaction: adding a formaldehyde solution into the phosphoramide solution obtained in the step 1), heating to 60-80 ℃, and reacting for 0.5-2 h to obtain a solution B; mixing the obtained solution B with polyether polyol, heating to 60-160 ℃, and reacting for 1-6 h; and finally, vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 90-120 ℃ to remove residual monomers, so as to obtain the flame-retardant polymer polyol.

2. The method of preparing a flame retardant polymer polyol according to claim 1, wherein in step 1); dissolving organic diamine in an organic solvent, dropwise adding the organic diamine into the solution A, reacting for 1-3 h at-5 ℃, and then heating to 40-60 ℃ for reacting for 1-3 h; adding an acid-binding agent, reacting for 1-3 h at 40-60 ℃, and finally filtering to obtain a colorless and transparent phosphoramide solution.

3. The method of preparing a flame retardant polymer polyol according to claim 1, wherein in step 2): mixing the obtained solution B with polyether polyol, and heating to 80-100 ℃ for reaction for 1-3 h; and finally, vacuumizing under the conditions that the pressure is-0.098 MPa to-0.08 MPa and the temperature is 90-120 ℃ to remove residual monomers, so as to obtain the flame-retardant polymer polyol.

4. The method for preparing a flame retardant polymer polyol according to claim 1, wherein a reaction promoter is further added to the solution a of step 1), wherein the reaction promoter is selected from halogen metal salts; the addition amount of the reaction promoter is 0.0001-2% of the total mass of the phosphamide solution.

5. The method of making a flame retarded polymer polyol according to claim 4, wherein said reaction promoter is selected from the group consisting of iodide or bromide salts; the addition amount of the reaction promoter is 0.05-0.2% of the total mass of the phosphamide solution.

6. The method of claim 5, wherein the reaction promoter is selected from potassium iodide or sodium iodide.

7. The method of any of claims 1-6, wherein the phosphoryl dichloride has the formula:

wherein R is C₁~C₈Alkyl, alkenyl, alkynyl, cycloalkyl or C₆~C₈Any of the phenyl groups of (a).

8. The method of claim 7, wherein R is C₁~C₈Alkyl or C₆~C₈A phenyl group of (a).

9. The method of any of claims 1 to 6, wherein the organic solvent is selected from aprotic solvents of ethers, amides, halogenated hydrocarbons, saturated alkanes, aromatic hydrocarbons or sulfones; the phosphoryl dichloride and the organic diamine are dissolved in different or same organic solvents, the mass ratio of the organic solvent used for dissolving the organic diamine to the organic diamine is 2: 1-6: 1, and the mass ratio of the organic solvent to the phosphoryl dichloride in the solution A is 2: 1-6: 1.

10. The method of claim 9, wherein the organic solvent is selected from the group consisting of 2-6 carbon containing ethers or cyclic ethers, 3-6 carbon containing amides or alkyl substituted amides, 1-3 carbon containing saturated chloroalkanes, halobenzenes, 3-13 carbon containing sulfones; the mass ratio of the organic solvent used for dissolving the organic diamine to the organic diamine is 2: 1-3: 1, and the mass ratio of the organic solvent to the phosphoryl dichloride in the solution A is 2: 1-3: 1.

11. The method of claim 10, wherein the organic solvent is selected from one or more of tetrahydrofuran, dimethylformamide, dimethylacetamide, dioxane, and methylene chloride.

12. The method of making a flame retarded polymer polyol according to claim 11, wherein said organic solvent is dioxane.

13. The method of any of claims 1 to 6, wherein the organic diamine is selected from one or more of ethylene diamine, 1,2 or 1,3 diaminopropane, 1,4 diaminobutane, 1,6 diaminohexane, p-phenylenediamine.

14. The method of claim 13, wherein the molar ratio of organic diamine to phosphoryl dichloride is 2:1 to 3: 1.

15. The method for preparing the flame retardant polymer polyol according to any one of claims 1 to 6, wherein the acid scavenger is selected from one or more of sodium carbonate, triethylamine, pyridine and trimethylamine.

16. The method of claim 15, wherein the molar ratio of acid scavenger to phosphoryl dichloride is 2:1 to 2.1: 1.

17. The method for preparing the flame retardant polymer polyol as claimed in any one of claims 1 to 6, wherein the formaldehyde solution is a 37% aqueous solution, and the molar ratio of formaldehyde to phosphoramide is 1:1 to 2: 1; the mass ratio of the total amount of the formaldehyde and the phosphoramide to the polyether polyol is 0.1-0.6.

18. The method of claim 17, wherein the molar ratio of formaldehyde to phosphoramide is 1.2:1 to 1.6: 1.

19. The method for preparing a flame retardant polymer polyol according to any one of claims 1 to 6, wherein the polyether polyol is one or more of polyethylene oxide polyol and polypropylene oxide polyol.

20. The method of claim 19, wherein the polyether polyol has a hydroxyl number of 20 to 60, a functionality of 2 to 6, and a molecular weight of 2000 to 8000.

21. The flame-retardant polymer polyol prepared by the method of any one of claims 1 to 20, which contains 6 to 9% of nitrogen and 3 to 5% of phosphorus by weight of the polymer polyol, and can be used in the field of polyurethane synthetic materials.

22. The flame retarded polymer polyol polyurethane foam according to claim 21, wherein said polyurethane foam has a foam oxygen index up to 30%.